Extensible actuator with improved sealing means



July 18, 1967 w. SEABLOM EXTENSIBLE ACTUATOR WITH IMPROVED SEALING MEANSFiled June 6, 1966' INVENTOR. Wendell (NM!) Saab/om BY Attorneys L\ g 44 5. F e i! 3 a Q. m w a a r\ 6 M 4 6 5 x 2 I "a w W 4I(\ .lh\ J w 4 mUnited States Patent 3,331,292 EXTENSIBLE ACTUATOR WITH IMPROVED SEALINGMEANS Wendell Seablom, Santa Rosa, Calilrl, assignor to ControlledMercury Switch Corporation, Santa Rosa, Calif.,

a corporation of California Filed June 6, 1966, Ser. No. 555,633 4Claims. (Cl. 92-108) The present invention is a continuation-in-part ofmy copending application Ser. No. 407,255, filed Oct. 28, 1964, now US.Patent 3,263,929, which was a continuation-in-part of application Ser.No. 376,989, filed June 22, 1964, and now abandoned, which was acontinuationin-part of application Ser. No. 316,716, filed Oct. 16, 1963and now abandoned.

This invention relates to sprinkler heads and systems of a typeemploying extensible heads as are particularly useful in overheaddistribution of water to lawns and other crops.

In spraying water onto lawns from sprinkler heads disposed at variouslocations about the terrain, it is often desirable in fixedinstallations to have the sprinkler head mounted flush with or below theground. This is particularly desirable, for example, when grass is to bemowed or other crops harvested. On the other hand, it is not unusual todesire the sprinkler head to discharge a stream of liquid from aposition well above the ground level. For example, to minimize the pipelayout, it may be desired to locate sprinkler heads in the midst ofshrubbery or other obstructions. In such a case, it can be useful tohave a sprinkler head originate a stream of liquid from a raisedposition to discharge over the top of the shrubbery or the like.However, if the head is fixed in place it can become an annoyance whenworking in and about the shrubbery.

Consequently, it is a general object of the present invention to providean improved extensible sprinkler head.

In extensible sprinkler devices, it is usually desirable that leakage beminimized to conserve water and maintain the premises.

Another object of the invention is the provision of an extensiblesprinkler head provided with improved means for insuring against leakageboth within the device and out of the device.

Other objects of the invention will be pointed out in the followingdetailed description of a preferred embodiment of the invention whenconsidered in conjunction with the accompanying drawings.

In the drawings:

FIGURES 1 and 2 are elevation section views showing a sprinkler head,according to the invention, in its projected and retracted positionsrespectively.

In general, a sprinkler head has been provided herein of a type whereina member is formed to provide an elongated cylinder and another memberprovides a piston movable between advanced and retracted positionswithin the cylinder. The piston is formed with a portion disposed to beextensible with respect to one end of the cylinder. The piston and theextensible portion are formed with a flow passage to pass liquid'fromone side thereof to be discharged on the other form from the end of theextensible portion outside the cylinder.

A valve member is carried by the cylinder and telescopically coacts withthe piston in order to block the flow passage when the piston is in itsretracted position and to open the flow passage when the piston is inits advanced position. The cylinder is arranged to include means servingto pass liquid under pressure into the cylinder to one side of thepiston in order to move the piston to its advanced position and therebyopen the flow 3,331,292 Patented July 18, 1967 passage. The appliedliquid then passes through the flow passage and discharges out theextensible portion.

Means for providing improved sealing against leakage internally andexternally of the sprinkler device have been provided using resilientO-rings but arranged to cooperate with laterally enlarged or constrictedzones formed to slidably engage and laterally press increasingly againstthe O-rings as the piston arrives at its advanced or retractedpositions.

Referring to FIGURES 1 and 2 there is shown an embodiment particularlysuitable for manufacture by injection molding techniques andincorporating features and advantages as now to be described. A bodyshell construction generally designated 5 having means for passing fluidinto and out of a cylinder 6 is assembled from a number of injectionmolded parts. Thus a cylindrical body member 7 is formed to providecylinder 6. A fluid passage 8 is provided at the bottom of body member 7for passing fluid into and out of cylinder 6. Water under pressure forspray distribution will normally enter passage 8 from a water pipe suchas indicated at 9. Another fluid passage 11 is formed at the upper endof cylinder 6 from an assemblage of parts to be described further belowwhereby further transverse forming operations are not required.

Passage 11 discharges fluid ahead of a piston assembly 10 as it movesupwardly within cylinder 6. Fluid discharging via passage 11 is directeddownwardly along the outside of body member 7 via downspout 13 whichstands free of the side wall of body member 7.

A hollow cylindrical post 14 is formed in a counter bored fashioncoaxially within cylinder 6. The lower end of post 14 is sealed closedby a plug 15 bonded to cover the open lower end. Plug 15 includes a stem15a which serves as a handle when inserting plug 15.

The lower end of bodymember 7 is formed with anchoring means serving tostabilize the sprinkler when buried. The anchoring means comprises askirt 17 of generally cylindrical construction bonded or otherwise fixedto the body member 7 to depend therefrom as an extension. A plurality offixed vanes 18 are provided, lying transversely of skirt 17 and bondedboth to the bottom of body member 7 and to skirt 17 so as to brace theskirt as well as to resist rotation of body member 7 when lodged in theground. Skirt 17 is formed to include a relieved portion 19 which servesto accommodate a transversely extending pipe adapted to be coupled, asby a suitable T or elbow connection to downspout 13.

A piston assembly includes a piston head portion 12 formed of an annularmember 23 bonded to a generally flanged end portion 24 formed on thelower end of an elongated hollow piston extension 26. Flanged portion 24includes an annular rib 27 inserted and bonded into a circular grooveformed in the upper surface of member 23. In this manner a pair ofO-rings 28 can be captured around the inner and outer circumference ofthe piston head 12. Members 23 and 24 then are bonded together in aconventional manner by bonding cement.

At the upper end of the cylinder 6 fluid passage 11 serves to pass fluidinto and out of cylinder 6. The upper end of cylinder 6 is otherwiseclosed by a transversely extending molded end member 29 formed at theupper end of downspout 13. The lower end of downspout 13 is braced bybeing passed through a rigid guide 31.

A cap 33 cooperates with a groove formed in the upper edge of member 29so as to capture an O-ring 34 therebetween. O-ring 34 serves to form aseal around piston extension 26 during its movement between retractedand advanced positions.

At the upper end of piston extension 26 a spray element or other fluiddischarge means 36 threadedly engages a counter bored portion 37 of 26.Therefore, various types of spray elements can be employed with the samebasic elevator device.

Alignment means serve to maintain radial positioning of spray element 36with respect to body member 7. Thus, a tongue 38 is fixed with respectto extension 26 and locked in place by spray element 36. The lower endof tongue 38 is slidably engaged through a slot 47 formed through theupper end of the post 14. The length of tongue 38 is such that pistonhead 12 abuts the upper end of cylinder 6 before the lower end of tongue38 passes out of slot 47.

As thus arranged it will be clear that tongue 38 serves to maintainradial alignment of extension 26 during movement between retracted andprojected positions without interfering with the operation thereof.Extension 26 therefore will not be rotated to cause the orientation ofspray element 36 to be misdirected with respect to its assigned regionof coverage.

Slot 47 formed in the upper end of post 14 serves to guide tongue 38 byslidable engagement therebetween.

If it were not for the constricting nature of slot 47 in post 14, tongue38 would be permitted to be rotated with respect to post 14 due to theenlarged hollow interior dimension of post 14. Thus it will be apparentthat slot 47 forms a constriction in the hollow interior of post 14which precludes rotation thereof during projection and retraction of thepiston assembly.

Tongue 38 is formed, however, with a relieved portion disposed toregister adjacent slot 47 when piston extension 26 is in its retractedposition. The relieved region more particularly is shown as the neckeddown relieved portion 40 which is formed to include a transverselyextending ledge 41 on opposite sides of tongue 38. The relieved portion40 is dimensioned so as to clear the constriction formed by slot 47 andpermit rotation between tongue 38 and post 14 so as to dispose theledges 41 beneath the overhanging lip 42 of slot 47.

Frequently, it is desired to change spray elements 36. For this purposea hexagonal nut 49 or the like is formed at the upper end of element 36.When a wrench is applied to nut 49 a considerable torque can bedeveloped upon the piston extension 26 which, if not dissipated throughthe body of the apparatus, can serve to rupture or otherwise damage thedevice, such as by twisting tongue 38.

Means are provided whereby torque applied to extension 26 is transmittedto body construction via L-shaped vanes 51.

Thus when extension 26 is in its retracted position the necked downregion 40 serves to permit the piston assembly to be rotated withincylinder 6. Beneath the piston head, annular member 23 is formed withthree downwardly extending abutments 43. Each abutment 43, whenextension 26 is in its retracted position, extends downwardlysufliciently to engage the upper end of L-shaped upright vanes 51whereby rotation of the abutments 43 with respect to vanes 51 willultimately be limited by engagement therebetween. Accordingly, theabutment means serves to transfer torque applied to extension 26 intothe body construction of the head assembly.

The upper end of post 14 includes a plurality of grooves 44 extendingalong the outer surface of post 14 which functions as a valve member.Grooves 44 are disposed to be encircled by a sealing ring, such as theresilient O-ring 28 at a position inter-mediate the ends of grooves 44when the piston is in its advanced position. In this manner fluid canpass from cylinder 6 int-o the hollow interior of extension 26 to bedischarged via spray element 36. Thus, sealing rings 28 is alwaysmaintained in place by the exterior surface of post 14. It will befurther noted that the upward travel of the piston is limited by moldedend cap member 29 so as to define the advanced position of pistonassembly at a point which is reached prior to carrying sealing ring 28upwardly beyond the end of post 14.

To insure against leakage internally, and externally, O-rings 28 and 34are positively compressed increasingly as piston assembly 1t arrives atits projected and retracted positions.

Thus, a zone 30 extending continuously around the interior wall surfaceof body member 7 bulges inwardly slightly and gradually to provide atapered reduction in the diameter of cylinder 6 on the order of .008inch for a body member 7 otherwise having an inside diameter on theorder of 1 /3 inches. When piston assembly 10 is moved to its retractedposition, zone 30 compresses the outer O-ring 28 radially inwardly topositively insure against leakage past piston head 12 at zone 39. Asimilar radially inward constriction zone 32 is formed around the upperend of cylinder 6 so as to cooperate with the outer one of O-rings 28 aspiston head 12 arrives at its advanced position.

At the level of zone 30 post 14 has been enlarged to form a sealing zone35 extending continuously around post 14. The tapered enlargement ofzone 35 runs to a maximum increase in post diameter on the order of .008inch. Zone 35 cooperates with the radially inner one of O-rings 28whereby as piston head 12 arrives at its retracted position, radiallyoutward compression is positively applied to the O-ring to insure propersealing.

Further, piston extension 26 includes lower and upper sealingenlargements forming zones 45, 46 respectively, each of which slightlyenlarges the diameter of extension 26 and extends continuously aroundextension 26. Zones 45, 46 are disposed axially of extension 26 tocooperate with the O-ring 34 carried around the opening through whichextension 26 moves, so that as piston assembly 10 arrives at either itsretracted or advanced positions, positive sealing developes byincreasingly compressing O-ring 34 thereat.

A pressure system of a type, for example, as shown in the aboveidentified US. Patent 3,263,929 controls the movement of piston assembly10. Thus pressure applied to assembly 10 to raise it to an advancedposition enters fluid passage 8 to apply pressure to the underside ofthe piston head portion 12. Fluid ahead of piston head portion 12exhausts via downspout 13. In order to retract piston extension 26 thefluid pressure system is reversed so as to apply pressure to the fluidpassages defined by downspout 13 and to exhaust fluid via passage 8.Suitable means for reversing the fluid pressure connections to thesystem are shown in the above identified patent, for example, at FIGURE1 thereof.

What is claimed is:

1. In a fluid operated actuator of a type for moving an element betweenadvanced and retracted positions, a cylinder, a piston movable alongsaid cylinder between advanced and retracted positions, fluid passagemeans at opposite ends of said cylinder for supplying fluid underpressure to one side of said piston and for exhausting fluid from theother side to move said piston between said positions, a memberextending axially within the cylinder and telescopically receivedthrough said piston, a resilient -O-ring carried by said piston to forma seal between said member and the piston during movement of the pistontherealong, said member including a slightly enlarged portion extendingcontinuously therearound and axially disposed to increasingly compresssaid O-ring as said piston arrives at its retracted position.

2. In a fluid operated actuator of a type for moving an element betweenadvanced and retracted positions, a first member forming cylinder, asecond member forming piston movable along said cylinder betweenadvanced and retracted positions, fluid passage means at opposite endsof said cylinder for supplying fluid under pressure to one side of saidpiston and for exhausting fluid from the other side to move said pistonbetween said positions, a third member extending axially within thecylinder and telescopically received through said piston, a firstresilient O-ring carried by said piston to form a seal between saidthird member and the piston during movement of the piston therealong,said third member including a slightly enlarged portion extendingcontinuously therearound and axially disposed to increasingly compresssaid O-ring as said piston arrives at its retracted position, a secondresilient O-ring carried by one of said first and second members forsliding engagement with a surface of the other of said first and secondmembers, said surface tapering slightly radially of said other member ina zone thereof extending continuously around said other member, saidzone being axially disposed to cooperate with said second O-ring at oneof said advanced and retracted positions of said second member toincreasingly compress said second O-ring thereat.

3. In apparatus of a type having a hollow body shell, 1

a piston movable between retracted and advanced positions within saidbody shell wherein the piston includes a hollow extension protruding viaan opening out of an end of the body shell and carries a spout elementsupported by said extension for discharging fluid therefrom,

and further having first fluid passage means for passing fluid underpressure into said body shell at one end thereof to move said pistontoward the other end of said body shell, and second fluid passage meansat said other end for passing fluid lying ahead of said piston out ofsaid shell, the improvement comprising a resilient O-ring encirclingsaid piston and slidably engaging the interior wall of said body shell,said body shell being slightly constricted peripherally therearound tocooperate with said O-ring at one of said advanced and retractedpositions of said piston to increasingly compress said O-ring thereat,another resilient O-ring, the last named O-ring being disposed aroundsaid opening and disposed between said extension and said body shell,said extension being slightly radially enlarged to cooperate with thelast named O-ring at one of said advanced and retracted positions ofsaid piston to increasingly compress the last named O- ring thereat,

4. In a fluid operated actuator of a type for moving an element betweenadvanced and retracted positions, a cylinder, a piston movable alongsaid cylinder between advanced and retracted positions, fluid passagemeans at opposite ends of said cylinder for supplying fluid underpressure to one side of said piston and for exhausting fluid from theother side to move said piston between said positions, a resilientO-ring encircling said piston and slidably engaging the interior wallsurface of said cylinder, said wall surface tapering slightly radiallyinwardly in a zone thereof extending continuously around said cylinder,said zone being axially disposed to cooperate with said O-ring at one ofsaid advanced and retracted positions of said piston to increasinglycompress said O- 5 ring thereat, an extension carried by said piston toprotrude through an opening in one end of said cylinder, a resilientO-ring carried around said opening and disposed for sliding engagementwith the periphery of said extension, the periphery of said extensionbeing slightly enlarged at a zone thereof extending continuously aroundsaid extension, the last said zone being disposed axially of saidextension to cooperate with the O-ring around said opening at one ofsaid advanced and retracted positions to increasingly compress samethereat.

References Cited UNITED STATES PATENTS 1,484,888 2/1924 Johnson 239-2041,495,949 5/1924 Carroll 92110 2,595,598 5/1952 Morton 239-204 3,063,42511/1962 Be Vier et al 92-108 X 3,203,246 8/1965 Horwitt et 'al. 251 XMARTIN P. SCHWADRON, Primary Examiner. I. C. COHEN, Assistant Examiner,

2. IN A FLUID OPERATED ACTUATOR OF A TYPE FOR MOVING AN ELEMENT BETWEENADVANCED AND RETRACTED POSITIONS, A FIRST MEMBER FORMING CYLINDER, ASECOND MEMBER FORMING PISTON MOVABLE ALONG SAID CYLINDER BETWEENADVANCED AND RETRACTED POSITIONS, FLUID PASSAGE MEANS AT OPPOSITE ENDSOF SAID CYLINDER FOR SUPPLYING FLUID UNDER PRESSURE TO ONE SIDE OF SAIDPISTON AND FOR EXHAUSTING FLUID FROM THE OTHER SIDE TO MOVE SAID PISTONBETWEEN SAID POSITIONS, A THIRD MEMBER EXTENDING AXIALLY WITHIN THECYLINDER AND TELESCOPICALLY RECEIVED THROUGH SAID PISTON, A FIRSTRESILIENT O-RING CARRIED BY SAID PISTON TO FORM A SEAL BETWEEN SAIDTHIRD MEMBER AND THE PISTON DURING MOVEMENT OF THE PISTON THEREALONG,SAID THIRD MEMBER INCLUDING A SLIGHTLY ENLARGED PORTION EXTENDINGCONTINUOUSLY THEREAROUND AND AXIALLY DISPOSED TO INCREASINGLY COMPRESSSAID O-RING AS SAID PISTON ARRIVES AT ITS RETRACTED POSITION, A SECONDRESILIENT O-RING CARRIED BY ONE OF SAID FIRST AND SECOND MEMBERS FORSLIDING ENGAGEMENT WITH A SURFACE OF THE OTHER OF SAID FIRST AND SECONDMEMBERS, SAID SURFACE TAPERING SLIGHTLY RADIALLY OF SAID OTHER MEMBER INA ZONE THEREOF EXTENDING CONTINUOUSLY AROUND SAID OTHER MEMBER, SAIDZONE BEING AXIALLY DISPOSED TO COOPERATE WITH SAID SECOND O-RING AT ONEOF SAID ADVANCED AND RETRACTED POSITIONS OF SAID SECOND MEMBER TOINCREASINGLY COMPRESS SAID SECOND O-RING THEREAT.